aliskiren

Aliskiren is an oral direct renin inhibitor used to treat hypertension. By binding selectively to the active site of renin, it blocks the conversion of angiotensinogen to angiotensin I, reducing the formation of angiotensin II and thereby decreasing vasoconstriction and aldosterone-mediated sodium retention.

The drug is available as film-coated tablets, commonly in 150 mg and 300 mg strengths. It can be prescribed as monotherapy or in combination with other antihypertensives, such as thiazide diuretics. It is taken once daily, with or without food, and dosage is typically started at 150 mg and may be increased to 300 mg daily depending on response and tolerability.

Pharmacokinetics show that aliskiren has relatively low oral bioavailability and achieves peak plasma concentrations within a few hours. The elimination half-life is roughly one day, and the drug is excreted largely unchanged in the feces with minimal hepatic metabolism.

Common adverse effects include dizziness, diarrhea, and fatigue. Hyperkalemia can occur, particularly in patients with reduced kidney function or those taking other potassium‑altering medications. Hypotension is a potential risk, especially with dehydration or concurrent antihypertensive therapy. Rare adverse effects include angioedema.

Contraindications include pregnancy, due to fetal toxicity. Caution is advised in patients with renal impairment, volume depletion, or significant electrolyte disturbances. In certain patients, concomitant use with ACE inhibitors or ARBs is discouraged, especially in those with diabetes or renal impairment, due to increased risk of kidney dysfunction and hyperkalemia. Drug interactions may involve potassium‑seeking agents and, to a lesser extent, P‑glycoprotein inhibitors, which can raise aliskiren exposure. The ALTITUDE trial noted no added benefit and potential harm when aliskiren was used with ACE inhibitors or ARBs in type 2 diabetes with nephropathy, influencing labeling and use recommendations.